1. Field of the Invention
The invention relates to a mass for dummy target production.
2. Description of the Prior Art and Related Subject Matter
Objects to be protected such as ships, drilling platforms, tanks, etc., have large surfaces with relatively low surface temperatures for example approximately 0.degree. to 20.degree. C. for a chassis or a hull and a maximum of 80.degree. to 100.degree. C. for a chimney or stack. Thus, according to Planck's radiation law, this means that such objects to be protected have the simultaneous features of low radiant intensities in the short wave infrared range (SWIR range 2 to 2.5 .mu.m) and high radiant intensities in the medium wave infrared range (MWIR range 3 to 5 .mu.m) and long wave infrared range (LWIR range 8 to 14 .mu.m).
Homing missiles such as so-called two-color infrared homing missiles are able to differentiate between radiant intensities in the SWIR range and those in the MWIR range. For detecting and tracking a target the homing missiles detect radiant intensities in the MWIR range and at the same time are able to establish radiant intensities in the SWIR range for discriminating with respect to dummy targets.
German patent application P 42 38 038.3 (not published before the filing date of the present application), corresponding to U.S. Pat. No. 5,397,236 issued Mar. 14, 1995 entitled "Method for Offering a Composite Dummy Target Formed From a Plurality of Active Masses Which Emit Spectrally Differentiated Radiation," Fegg et al., filed Nov. 12, 1993, discloses a method for providing a dummy target body, which is used for simulating the target signature of an object to be protected for an imaging homing missile, wherein flare masses are made to explode in a spatially and time displaced manner at the location of the dummy target body to be formed. The flare mass according to P 42 38 038.3 is composed of a mixture of phosphorus granules and small phosphorus flares and has a spectral radiant flux with a desired high percentage in the MWIR range, but the overall radiant intensity in the SWIR range clearly exceeds that of objects to be protected. Therefore homing missiles classify dummy targets produced according to P 42 38 038.3 as an illusion due to the radiant flux in the SWIR range and consequently do not home on dummy targets.
German OS 26 14 196 discloses an infrared radiator, which is produced by an incendiary composition formed from potassium nitrate and metallic boron or gunpowder or solid propellants, the burn-off temperature being higher than an object temperature of approximately 20.degree. C. Thus, according to Planck's radiation law or Wien's displacement law the maximum of the radiant flux of the dummy target produced according to German OS 26 14 196 is at lower wavelengths than the maximum of the radiant flux of an object to be protected, which makes it possible for homing missiles to distinguish the dummy target from the target object.
German OS 35 15 166 describes a projectile for representing an infrared surface radiator, whose flare mass is formed from phosphorus, together with aluminum hydroxide used for passivating phosphorus, in order to slow the extinguishment time. The dummy target produced according to German OS 35 15 166 has a not negligible radiant flux percentage in the SWIR range, so that homing missiles can distinguish a dummy target from an object to be tracked. The addition of aluminum hydroxide only leads to a slight change in the specific gravity of the flare mass, which leads to no slowing of the action time of the flare mass or to the life of the dummy target.
German OS 23 59 758 discloses a flare mass of the type having an incendiary composition component and an inert component in which the inert component comprises metal carrier foils, which are coated with an incendiary composition component. This known flare mass is an infrared interference radiator, in which the weight or quantity ratio between the incendiary composition component and the inert component is optimized from the standpoint of extending the radiation time by slowing extinguishment but there is no mention of an adaptation of the radiant flux distribution to that of the target signature to be simulated.